Structural organization of the perivascular astrocyte endfeet and their relationship with the endothelial glucose transporter: A confocal microscopy study

Despite the increasing evidence for a prominent role played by the perivascular endfeet of astrocytes in the functional metabolic coupling between astrocytes and neurons, a clear picture of their spatial organization is still lacking. To examine the three‐dimensional structure of the astrocyte endfeet and their relationships with the endothelial cells, coronal rat brain sections immunolabeled for the two astroglial markers [glial fibrillary acidic protein (GFAP)/S‐100β] and the endothelial glucose transporter (GLUT1) were analyzed under the confocal microscope. Double immunolabeling of GFAP and S‐100β showed numerous well‐defined astrocytes sending one or more endfeet to the vasculature. Examination of GFAP immunolabeling at higher magnification showed that these endfeet consist of well‐defined rosette‐like structures lying on the vessel wall.

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